A system may include a host device and multiple devices in communication with the host. An example of a system configuration is depicted in FIG. 1, in which the host device uses a network topology known as a “ring”. “Ring” topology is a type of network setup in which the multiple devices are connected in series, with the first device and the last device of the multiple devices being connected directly to the host device. The transmitter circuit (Tx) of the host device is connected to the receiver circuit (Rx) of Device1. The transmitter circuit (Tx) of Device1 is connected to the receiver circuit (Rx) of Device2, and this operation is repeated. The transmitter circuit (Tx) of Device N, which is the final device in the system, is connected to the receiver circuit (Rx) of the host device, thereby completing the ring connection. Other examples of system configurations include a tree topology, a star topology, a linear daisy chain topology, or a hub topology.
Prior to normal operation of the system, one or more of the multiple devices may be initialized. There are several ways in which to initialize the one or more multiple devices. One way is to sequentially initialize the multiple devices. Sequential initialization involves initializing the multiple devices one-at-a-time in series, starting with the first device (Device 1 in FIG. 1) and ending with the last device (Device N in FIG. 1). Sequential initialization has both benefits and drawbacks. This type of initialization consumes relatively low power at any single time so as not to exceed the power capability of the host device. However, because initialization is performed one device at a time, sequential initialization takes a long time.
Another way to initialize the system is parallel initialization. Parallel initialization involves initializing all of the multiple devices at once. Parallel initialization has the benefit of quick initialization. However, parallel initialization consumes relatively high power during system initialization time. In particular, each of the multiple devices consumes current during the initialization (such as 100 milliamp (mA)). The host device may include a power supply that is capable of operating during the normal operation, but incapable of performing the parallel initialization. For example, the host device may include a power supply with a 400 mA output. In the event that the system includes more than 4 devices (each requiring 100 mA during initialization), the power supply cannot initialize all of the devices in parallel. To perform the parallel initialization, the host device must have a larger power supply at a greater cost.
Accordingly, both sequential initialization and parallel initialization unduly suffer from power or time constraints.